College of Science Guilin University of Technology Guilin 541004 China;
College of Science Guilin University of Technology Guilin 541004 China;
College of Science Guilin University of Technology Guilin 541004 China;
School of Optoelectronic Engineering Guangdong Polytechnic Normal University Guangzhou 510665 China;
College of Science Guilin University of Technology Guilin 541004 China;